#include <iostream>

int main()
{
	double number = 0.0;

	std::cout << "Enter number: ";
	std::cin >> number;
	
	double vec[20];
	int n = 1;

	std::cout << "Enter array" << std::endl;

	do
	{
		std::cout << "Enter number" << n << " or -1 to quit: ";
		std::cin >> vec[n];
		n++;
	}
	while(vec[n-1] != -1);

	std::cout << "Index: ";

	for(int i = 1; i < n; ++i)
		if(vec[i] == number)		
		{
			std::cout << i << " ";
		}	

	std::cout << std::endl;
	
	return 0;
}